package CodingTest;

import javax.imageio.ImageIO;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.util.Random;

@WebServlet("/checkCodeServlet")
public class checkCodeServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        this.doPost(req,resp);
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        int width=100;
        int height=50;

        //1.创建一对象,在内存中画图片(验证码图片对象)
        BufferedImage image=new BufferedImage(width,height,BufferedImage.TYPE_INT_BGR);

        //2.美化图片
        //2.1填充背景色
        Graphics g=image.getGraphics();//画笔对象
        g.setColor(Color.pink);//设置画笔颜色
        g.fillRect(0,0,width,height);

        //2.2画边框
        g.setColor(Color.blue);
        g.drawRect(0,0,width-1,height-1);

        String str="qwertyuiopasdfhjklzxcvbnmQWERTYUIOPASDFGHJKLZXCVBNM1234567890";
        Random r=new Random();

        for (int i = 1; i <=4 ; i++) {
            int index=r.nextInt(str.length());
            char ch = str.charAt(index);

            //2.3写验证码
            g.drawString(ch+"",width/5*i,height/2);
        }

        //2.4画干扰线
        g.setColor(Color.green);
        for (int i = 0; i < 10; i++) {
            int x1 = r.nextInt(width);
            int x2 = r.nextInt(width);

            int y1 = r.nextInt(height);
            int y2 = r.nextInt(height);
            g.drawLine(x1,y1,x2,y2);
        }

        //3.将图片输出到页面展示
        ImageIO.write(image,"jpg",resp.getOutputStream());


    }
}
